public function getServerId($server) {
    $serverId = 0;
    $sql = <<<_SQL_
        SELECT s.serverId
        FROM servers s
        WHERE s.name = ?
        LIMIT 1
_SQL_;

    $stmt = $this->DB->stmt_init();
    if ($stmt->prepare($sql)) {
      $stmt->bind_param('s', $server);
      $stmt->execute();
      $stmt->bind_result($serverId);
      if (!$stmt->fetch())
        $serverId = 0;
    }
    $stmt->close();
    return $serverId;
  }